Fuse link head



Oct. 4, 1932. T. BIRKENMAIER FUSE LINK HEAD Filed Jan. 17. 1930 Patented Oct. 4, 1932 UNITED STATES PATENT OFFICE THEODORE BIRKENMAIEB, OF ST. LOUIS, MISSOURI, ASSIGlfOB TO W. N. MATTHEWS CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI FUSE LINK HEAD Application filed January 17, 1930. Serial No. 421,393.

This invention relates to fuses, and with regard to certain more specific features, to fuse links provided with contacting heads.

Among the several objects of the present invention may be noted the provlsion of a fuse link having a contacting head adapted to seal against gas leakage; and the provisi on of a fuse link head whichis simple in construction, effective, rugged, and requires only a minimum amount of labor in construction. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structure hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing, in which are illustrated three of various possible embodiments of the invention,

Fig. 1 is a vertical section ofa fuse llnk holder unit or cartridge showing the meth- 0d of holding a fuse link therein;

Fig. 2 is a horizontal view taken on line 22 of Fig. 1 showing the applicatlon of an old form of fuse link head;

Fig. 3 is a perspective View of a fuse link of the ordinary type;

Fig. 4c is a plan view showing a preferred form of my invention wherein the head 1s composed of two pieces fastened to the fuse link;

Fig. 5 is a cross section taken on line 55 of Fig. 4L;

Fig. 6 is a plan view of another form of my invention where the head comprises a single piece affixed to the fuse link;

Fig. 7 is a section taken on line 7-7 of Fig. 6;

Fig. 8 is an elevation of a third form of my invention, wherein the head is made from a piece of tubing, the view showing the head before a clamping operation has been performed; I

Fig. 9 is a sectional elevation of the head shown in Fig. 8 after the clamping operation has been completed, and showing the fuse link and head placed within the fuse holder; and,

Fig. 10 is a view taken on line 1010 of Fig. 9 and similar to Fig. 2, showing the application of the improved fuse head shown in Figs. 8 and 9.

Similar reference characters indicate corresponding parts throughout the several views of the drawing.

Referring now more particularly to Fig. 1, there are illustrated at numerals 1 and 3 metal contacting members adapted to engage with contacting jaws of afuse switch or the like. A tube 5 made of insulating material such as bakelite is screwed into contacting member 1 as shown at numeral 7 and passes through a hole 9 in member 3. A set screw 11 holds member 3 to tube 5.

At the upper end of member 1 there is provided an annular portion 13 threaded at 15. A metal cap 17 is provided which screws to member 1 and is of such a length that its inner top surface 19 can abut against the end 1231 of member 1 when screwed down on mem- The lower contact member 3 is threaded at 23 to receive a collar 25. The member 3 is also provided with a sloping face 27 which fits flush with a similar face 29 provided on the inner surface of collar 25 when said collar is screwed tight on member 3.

When inserting a fuse link 31, the cap 17 is removed and collar 25 loosened. Link 31 is then placed in tube 5 with the link head 33 resting on end 21 of tube 5. The lower end of fuse link 31, which protrudes from the lower end of tube 5, is bent as shown and the end 35 is placed between faces 27, 29 and collar 25 screwed tightly onto member 3. Positive holding action and contact is thereby assured between fuse link 31 and memher 3.

Cap 17 is then screwed down tightly onto serted in slot 57 and the material of the head member 1, thereby firmly holding head 33 against end 21 of member 1.

WVith the ordinary type of fuse link 31, such as is shown in Figs. 2 and 3, it will be noted that a head 33 is formed by folding over one end of the link. Such a method of forming the head provides contacting means but fails to provide a proper sealing actlon against escape of gases when the fuse blows.

It is clear (Fig. 1) that the lower end of tube is open and that the upper end is closed by means of cap 17. When fuse 31 blows, the engendered gases are forced out of the lower end of tube 5 because the upper end is closed. It will be realized, however, that a poor seal for the gases is provided by the fuse link head 33and the threaded cap 17. Referring to Figs. 2 and 3, it will be clear that head 33 does not completely cover the end of tube 5, but that openings 37 are left through which the gases may pass into the recesses of cap 17 and thence out through threads 15. It is apparent that regardless of how tightly cap 17 is screwed down, the head 33 does not provide a sealing action against the engendered gases. This is particularly true in view of the fact that the threads 15, for quick action, should be of coarse pitch and heavy, and hence are inherently leaky.

The spirit of this invention includes the provision of improved fuse heads of the type described hereinafter which completely seal the opening on which the heads rest thereby providing a means of sealing this opening against the engendered gases when the fuse blows.

Figs. 4 and 5 show a preferred form of fuse link head made from two circular pieces of metal 39, 41. These pieces 39, 41 are each provided with an ear 43, 45 punched from the respective pieces as shown (Fig. When these ears 43, 45 are punched, openings 47, 49 are formed in the pieces 39, 41

n. the disc piece 55.

respectively. When aflixing the head to the fuse link 31, the ear 43 of the upper piece 39 is placed through opening 49 of the lower piece 41 and the fuse link 31 is inserted between the ears 43, 45. The two head pieces and the fuse link are held together by a rivet or like device 51. The end 53 of the link 31 may either be cut off or else bent over into the opening 47, as shown,'so that the completed head presents a flat upper surface. \Vith such a flat head, the cap 17 (as shown in Fig. 1) may, when screwed tightly down, press the head into sealing engagement with tube 5.

A second form of head is shown in Figs. 6 and 7. The head is made from a single piece 55. A slot or serrated opening 57 of such a shape that it will nearly or snugly receive the fuse link 31 is stamped through The fuse link is then inis forced or pinched toward the fuse link as indicated at numeral 59, so that the link and the head are securely held together.

Figs. 8, 9 and 10 show a third form of head. A piece of cylindrical metal tubing is spread at one end to form a flange G1. The tube is then flattened as shown at numeral 63 to form a slot or oblong hole 65 for receiving the link 31. Between the flange 61 and the flattened portion '63 an almost round portion 67 is retained. The fuse link when made of aluminum or other material which is hard enough to withstand the clamping or pinching action, is placed in the slot 65 which might occur if the space 71 were not left at the lower end of the head.

When a tin link or a link made of material softer than aluminum is to be assembled with this type of head, the clamping action is omitted. The head is then used in the form t shown in Fig. 8 and the link and head are held together by pouring solder or the like into the hole '65.

Although a particular form of fuse holder and fuse link are described, the invention is not to be so limited. Other forms of holders than shown in Fig. 1 and other fuse links than represented by numeral 31 may be used.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In an electric fuse, a fuse link, a tube in which said fuse link is placed havin an opening, a head on one end of said fuse link, said head comprising two metal pieces one above the other which have ears punched therethrough, the ear of the upper piece passing through the opening in the lower piece made by punching the ear therefor, said fuse link being fastened between said ears.

2. A fuse comprising a link of fusible material, a non-fusible head thereon, said head being held to the link by squeezing the same around the link.

3. In a fuse link, the provision of a head therefor, said head comprising two metal ISO pieces one above the other which have ears punched therethrough, the ear of the upper piece passing through the opening in the lower piece made by punching the ear therefor, said fuse link being fastened between said ears.

4. In a fuse link, the provision of a head therefor, said head comprising a metal piece with a slot therethrough, said link fitting within said slot and held therein by forcing the metal of the head into pinching engagement with said link.

5. In a fuse link, the provision of a head therefor, said head being provided with a hole into which said link fits, said head and link being held together by forcing the metal of the head into pinching engagement with said link.

6. In an electric fuse, a fuse link, a tube in which said fuse link is placed having an opening, a head on one end of said fuse link, said head comprising a metal piece with a slot therethrough, said link fitting within said slot and held therein by forcing the metal of the head into pinching engagement with said link.

7. In an electric fuse, a fuse link, a tube in which said fuse link is placed having an opening, a head on one end of said fuse link, said head comprising a metal piece with a slot therethrough, said link fitting within said slot and held therein by forcing the metal of the head into pinching engagement with said link and means for holding said head in sealing contact with the opening in said tube through which said fuse link is adapted to be placed.

8. In an electric fuse, a fuse link, a tube in which said fuse link is placed having an opening, a head on one end of said fuse link, said head being provided with a hole into which said link fits, said head and link being held together by forcing the metal of the head into pinching engagement with said link.

9. In a fuse link, the provision of a head therefor, said head comprising a metal tube flared at one end to provide a flange thereon, the tubular portion being squeezed into gripping engagement with said fuse link inserted therein.

10. In a fuse link, the provision of a head therefor, said head comprising a metal tube flared at one end to provide a flange thereon,

" the tubular portion being s ueezed into the shape of the cross section 0 said link, said link held within said head by solder.

11. A fuse comprising a link of fusible material, a non-fusible head thereon of cylindrical form, said head being held to the link by squeezing the same around the link.

12. In a fuse link, the provision of a head, said head comprising a flanged portion at one end and a body portion for receiving said fuse link, part of said body portion being 

